C H Bond activation with 3d metals exploration of new directing group cross dehydrogenative couplings and natural product synthesis

Abstract

Site selective CH bond activation functionalization reactions have burgeoned as a utopian maneuver to inflate molecular complexity of simple organic molecules The concept accounts direct utilization of otherwise inert CH bond of organic molecules as a synthetic handle and renovates the synthetic policies as a greener alternative to traditional cross coupling reactions by avoiding the need of pre functionalized substrates Specifically the cross dehydrogenative couplings en route to CC and Cheteroatom bonds are very significant as it constitutes a twofold functionalization manifold in a single operation Designing 3d transition metal catalysed CH bond activation strategy to showcase challenging carbon carbon and carbon heteroatom bond forming reactions with applications in syntheses of bioactive molecules is the essence of this thesis newlineIn Chapter 1 an overview of transition metal catalyzed CH bond activation strategy with specific focus on directed CH functionalizations survey on different directing groups along with various strategic developments and critical challenges associated with CH activation methodology have been presented newlineChapter 2 deals with the design and execution of new directing group namely 12 aminophenylpyrazole 2APP for the activation of inert arene CH bonds with abundant copper catalysts Using 2APP derived aromatic amides various orthoselective CO and CN bond forming reactions have been established using inexpensive CuOAc2 Specifically based on cross dehydrogenative coupling aryl alkyl ethers and their deuterated congeners were prepared in high yields using only reagent amount of alcohols This etherification process displayed a wide substrate generality and remarkable functional group compatibility Further utility of this methodology was showcased through the formal synthesis of antiemetic drug metoclopramide newlineChapter 3 describes CH bond activation technology for the syntheses of valuable natural products amorfrutin A cajaninstilbene acid hydrangenol and macrophyllol Of note amorfrutin A is a lea